Friday, July 15, 2011
In hot weather, you typically need to drink more because you sweat more, especially if you’re exercising. Humidity also increases your water needs. When it’s humid and warm – a double whammy – you may need as much as two times more water than when it’s drier.
How water impacts your body: Your body releases heat by expanding blood vessels close to the skin’s surface (this is why your face gets red during exercise), resulting in more blood flow and more heat dissipated into the air. When you’re dehydrated, however, it takes a higher environmental temperature to trigger blood vessels to widen, so you stay hotter.
Dehydration also lowers your blood volume, so your heart must work harder to pump the reduced amount of blood and get enough oxygen to your cells, which makes everyday activities like walking up stairs – as well as exercise – more difficult.
Excerpted from Eating Well Magazine, July/August 2011